title: The IMAGINE instrument: first neutron protein structure and new capabilities for neutron macromolecular crystallography.
abstract: The first high-resolution neutron protein structure of perdeuterated rubredoxin from Pyrococcus furiosus (PfRd) determined using the new IMAGINE macromolecular neutron crystallography instrument at the Oak Ridge National Laboratory is reported. Neutron diffraction data extending to 1.65 Å resolution were collected from a relatively small 0.7 mm(3) PfRd crystal using 2.5 d (60 h) of beam time. The refined structure contains 371 out of 391, or 95%, of the D atoms of the protein and 58 solvent molecules. The IMAGINE instrument is designed to provide neutron data at or near atomic resolution (1.5 Å) from crystals with volume <1.0 mm(3) and with unit-cell edges <100 Å. Beamline features include novel elliptical focusing mirrors that deliver neutrons into a 2.0 × 3.2 mm focal spot at the sample position with full-width vertical and horizontal divergences of 0.5 and 0.6°, respectively. Variable short- and long-wavelength cutoff optics provide automated exchange between multiple-wavelength configurations (λmin = 2.0, 2.8, 3.3 Å to λmax = 3.0, 4.0, 4.5, ∼20 Å). These optics produce a more than 20-fold increase in the flux density at the sample and should help to enable more routine collection of high-resolution data from submillimetre-cubed crystals. Notably, the crystal used to collect these PfRd data was 5-10 times smaller than those previously reported.
authors.affiliation: Department of Molecular and Structural Biochemistry, NCSU, Raleigh, NC 27695, USA.
authors.forename: Flora
authors.initials: F
authors.lastname: Meilleur
authors.forename: Parthapratim
authors.initials: P
authors.lastname: Munshi
authors.forename: Lee
authors.initials: L
authors.lastname: Robertson
authors.forename: Alexandru D
authors.initials: AD
authors.lastname: Stoica
authors.forename: Lowell
authors.initials: L
authors.lastname: Crow
authors.forename: Andrey
authors.initials: A
authors.lastname: Kovalevsky
authors.forename: Tibor
authors.initials: T
authors.lastname: Koritsanszky
authors.forename: Bryan C
authors.initials: BC
authors.lastname: Chakoumakos
authors.forename: Robert
authors.initials: R
authors.lastname: Blessing
authors.forename: Dean A A
authors.initials: DA
authors.lastname: Myles
mesh_terms: D019843:Archaeal Proteins / Q000737:chemistry; D018360:Crystallography, X-Ray / Q000295:instrumentation / Q000379:methods*; D006860:Hydrogen Bonding; D046911:Macromolecular Substances / Q000737:chemistry*; D009502:Neutrons; D020027:Pyrococcus furiosus / Q000737:chemistry*; D012416:Rubredoxins / Q000737:chemistry*; D012542:Scattering, Radiation; D014961:X-Ray Diffraction
chemical_list: D019843:Archaeal Proteins; D046911:Macromolecular Substances; D012416:Rubredoxins
keywords: IMAGINE; neuton macromolecular crystallography; neutron diffraction; rubredoxin